I haven’t had any problems with mine, and I didn’t receive any warnings from the dentist. I do know I can’t use whitening toothpastes and such on them in case the abrasives remove the colour painting the tooth-artist-person put on.

Neat! I wonder if the people I know have ones made of a different material for some reason? Or maybe their dentists are over cautious, hah. My brother broke his two front teeth when he fell into a shovel handle as a kid, so he has crowns on those and they gave him some restrictions for food and discolorations. C’est la vie!